Closure assemblies have been employed with containers generally and have found particular use in the pharmaceutical industry. Pharmaceutical containers for liquids or for solids which are reconstituted by the addition of liquids have a piercable closure member such as a disc or stopper formed of rubber or other elastomers. They are also provided with a metallic cap, usually aluminum, to hold the stopper in place.
In many designs, particularly in the pharmaceutical industry, the stopper is covered by a protective device such as a cap until access to the contents of the container is needed. In one design, a central removable disc is detachably secured to the outer portion of the cap through the use of fracturable bridges. By lifting off this center disc portion, the stopper area is exposed and access to the contents is provided.
Another alternative technique is the use of a tear off cap which provides a hinged central portion at the top of the cap, to provide a grip for tearing off the cover over the stopper and around the top of the container. These systems include a cap portion and a pull tab section with lines or scores for guiding the direction of tear. The difficulty with these designs is that either the tear portion or the closure has a sharp edge which can inadvertently injure the user.
In some instances, it is desirable to remove the stopper, rather than expose it for puncture by a syringe. U.S. Pat. No. 4,384,653 discloses a tip-off cap and closure in which an upper tubular elongated portion provides the leverage for tipping or pushing the lower or skirt portion off of the container and simultaneously removing the rubber stopper. This type of system is effective when the stopper is to be removed, but is, of course, not useful when the only suitable access will be the use of a syringe.
It has become clear that the assembly of pharmaceutical products and container in the most economical manner possible allows the supplier to pass on economies and efficiencies to the ultimate user of the product. More importantly, when a design is provided which is free from problems during hoppering, sealing and other assembly steps, manufacturing efficiencies allow the manufacture to be much more competitive in supplying what is now becoming a major article of commerce.
What would be greatly desirable would be a way to remove a portion of the cap to expose the stopper, while not involving complicated assembly procedures. Even though the pharmaceutical industry is intensely concerned about the integrity of the product produced, including the closure components, it is also driven by the need for greater efficiency and speed. For example, if a process which is otherwise quite reliable can be operated at a significant faster average operating speed, the unit cost is reduced without any adverse effect on product quality and integrity.
Accordingly, there appear to be two conflicting goals in efforts made to improve the application of closures to containers, particularly those for high speed assembly in the pharmaceutical industry. On the one hand, it is desirable to increase the strength and durability of the closure prior to assembly, to avoid downtime and a significant number of rejected products. On the other hand, the need for quick, easy and convenient opening of the container requires an easily removed overcap portion. This is particularly true because the user of the product has become dependent on a certain degree of ease, convenience and efficiency in opening containers.
Thus, it would be a great advance in the art if a new and improved design could be provided which would substantially simplify the manufacturing process while at the same time maintain or even improve the ease of use of the container by the final user.
These and other objects will become more apparent upon a reading of the description which follows.